Safe drugs/ways to treat IBS during first trimester???

Hi all.
Been suffering through severe gas cramps and brick like constipation (sorry if TMI) which is compounded by the zofran and reglan I am on for nausea.
I've always had a touch of IBS but this is over kill, even for me- to the tune of up most nights moaning in pain.
Anyone deal with this and have any solutions (besides more fiber)???